B2345
DTC B2345
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.
DTC Descriptors
DTC B2345 13
- Seat Heater Disable Circuit Voltage Low / High Temperature
DTC B2345 42
- Seat Heater Disable Circuit Calibration Data Set Not Programmed
DTC B2345 4B
- Seat Heater Disable Circuit Calibration Not Learned
Diagnostic Fault Information
Circuit/System Description
The left and right rear seat heating elements are controlled by a common high current relay internal to the rear heated seat module (RHSM) and the low side by individual element control circuits. The RHSM connects the seat heater element supply voltage circuits for both seats to a common reference point. This reference point is biased to approximately 2.0 volts. Before the RHSM will allow heated seat operation, it checks to see if this reference voltage is shorted to ground or battery voltage. Once the module verifies that it is not closing to a shorted heating element, it allows heated seat operation. After which it continues to monitor for a shorted circuit.
Conditions for Running the DTC
The heated seat system is active.
Conditions for Setting the DTC
B2345 13
Any temperature sensor input that remains below 1.5 volts for more than 1 second.
B2345 42
This DTC will set if the RHSM calibration is not programmed.
B2345 4B
This DTC will set if the RHSM calibration is out of range.
Action Taken When the DTC Sets
The heated seat function for both rear passenger seats will be disabled.
Conditions for Clearing the DTC
* The current DTC will clear 3 seconds after the reference voltage returns to normal operating range and the power mode changes to OFF then back to ACC or RUN.
* The history DTC will clear after 50 consecutive fault-free ignition cycles have occurred.
Reference Information
Schematic Reference
Heated/Cooled Seat Schematics (Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
Rear Heated Seats Description and Operation (Rear Heated Seats Description and Operation)
Electrical Information Reference
* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing For Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Circuit/System Testing
B2345 13
1. Ignition OFF, disconnect the X2, X4 harness connectors at the RHSM.
2. Test for greater than 2.1K ohms between the signal circuit and low reference circuits listed below:
* Left rear seat cushion terminal 9 X4 and terminal 6 X2
* Right rear seat cushion terminal 20 X4 and terminal 8 X2
• If less than the specified range, test for a short between the signal and low reference circuits. If the circuits test normal, replace the appropriate seat cushion temperature sensor.
3. Test for greater than 2.0K ohms between the signal circuit and low reference circuits listed below:
* Left rear seat back terminal 19 X4 and terminal 5 X2
* Right rear seat back terminal 10 X4 and terminal 7 X2
• If less than the specified range, test for a short between the signal and low reference circuits. If the circuits test normal, replace the appropriate seat back temperature sensor.
4. If all circuits test normal, replace the RHSM.
B2345 42 or B2345 4B
If either DTC is set, replace the RHSM.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Rear Seat Cushion Heater Replacement (Rear Seat Cushion Heater Replacement)
* Rear Seat Back Cushion Heater Replacement (Rear Seat Back Cushion Heater Replacement)
* Control Module References (Programming and Relearning) for RHSM replacement, setup, and programming